Ring-shell projector

Abstract

A ring-shell projector capable of simple disassembly and reassembly. The underwater transducer has a driving ring and a pair of flexible diaphragms on either side of the ring with their rims attached to the ring. The ring is formed of an array of electrostrictive elements and spacer elements, each spacer element having a pair of radial, outward extensions. A pair of coupling rings are provided each adapted to be positioned between the rim of one flexible diaphragm and a corresponding array of spacer element extensions to provide sealing engagement between the flexible diaphragms and the driving ring. Besides simplifying the repair of a projector, the improved design is more versatile, allowing a single driving ring to be used with different sets of shells, having different resonance frequencies and/or bandwidths. Moreover, an expensive step in the construction of a ring-shell projector is obviated, namely, the bolt holes in the metal staves and the subsequent custom matching of the shell holes.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. An underwater transducer having a driving ring and a pair of flexible diaphragms on either side of the ring with their rims attached to the ring, the ring being formed of an array of electrostrictive elements and spacer elements, each spacer element having a pair of radial, outward extensions, a pair of coupling rings each adapted to be positioned between the rim of one flexible diaphragm and a corresponding array of spacer element extensions to provide sealing engagement between the flexible diaphragms and the driving ring. 
     
     
       2. An underwater transducer as defined in claim 1 wherein the coupling rings are L-shaped in cross-section and further comprising an annular gasket located between a portion of the rim of each diaphragm and a corresponding portion of the extension. 
     
     
       3. An underwater transducer as defined in claim 1 wherein each diaphragm is provided with tabs extending radially beyond the coupling rings and adapted to receive fastening means. 
     
     
       4. An underwater transducer as defined in claim 3 wherein the fastening means comprises a bolt supporting a spacing element between the tabs, thereby to determine the separation of the diaphragms from one another. 
     
     
       5. A method of assemblying an underwater transducer having a driving ring and a pair of flexible diaphragms on either side of the ring with their rims attached to the ring, the ring being formed of an array of electrostrictive elements and spacer elements, each spacer element having a pair of radially, outward extensions; the method comprising the steps of: assembling the driving ring;   machining the outward extensions to provide surfaces adapted to mate with corresponding surfaces of a pair of coupling rings;   assembling the coupling rings to the driving ring;   machining the rims of the diaphragms to provide surfaces adapted to mate with corresponding surfaces on outer portions of the coupling rings;   assembling the diaphragms to the coupling rings; and   securing the diaphragms to provide a sealed transducer assembly.